Preoperative Assessment of Hepatocellular Carcinoma with Split-Bolus Combined Phase Contrast-Enhanced Computed Tomography

: BACKGROUND The aim of this study was to investigate the feasibility of a split-bolus combined phase contrast-enhanced computed tomography protocol in evaluation of liver vasculature in hepatocellular carcinoma (HCC) patients for the purpose of surgery guidance. MATERIAL AND METHODS Two groups of patients were recruited for the study: 24 consecutive cases of HCC who underwent multiphasic CT examination, and 22 consecutive cases who afterwards underwent split-bolus combined phase CT examination. The multiphasic protocol included an unenhanced scan and 3 image acquisitions after contrast injection. The injection of contrast medium was 440 mgI/kg in a single bolus. The split-bolus combined phase protocol included unenhanced scan and combined phase. The injection of contrast medium was 440 mgI/kg for the first bolus and 220 mgI/kg for the second bolus. The vascular delineation was evaluated with Likert scales. The CT values were measured, and the contrast-to-noise ratio (CNR) was calculated. We also compared the effective radiation dose (ED) of the 2 protocols. RESULTS All mean CT values were significantly higher in the split-bolus protocol than in the multiphasic protocol (all P.05). The ED was significantly lower in the split-bolus protocol, corresponding to a dose reduction of 66% compared to the multiphasic protocol (P<.05). The scores of the branches of the hepatic vein in the split-bolus protocol were not lower than those in the multiphasic protocol. CONCLUSIONS For the preoperative HCC patients, the split-bolus combined phase CT examination meets the diagnostic requirement of surgical planning, with approximately 60% reduction in the radiation dose.